The present invention, in some embodiments thereof, relates to a thermal management of an object and, more particularly, but not exclusively, to a thermal management that incorporated thermoelectric elements.
Thermal management of an object is changing the temperature profile of an object. The change may be globally over the object or locally over part of the object and in general may be heating or cooling or both. Cooling or heating of an object may be done in various ways. The present invention is focus on cooling or heating using thermoelectric elements, i.e., elements that are using the thermoelectric effect.
The thermoelectric effect is the ability to convert heat flow energy directly to electricity. It was discovered by a Germen physicist, Seebeck, in 1821. The reverse effect on the same device, i.e., use of an electrical energy for heat pumping (enable heating but more important also enable cooling of an object) was discovered by a French physicist, Peltier, in 1834. This two reversible energy conversion operations are performed by generating electrical current by the thermoelectric device or driving electrical current to the thermoelectric device respectively. The thermoelectric basic element is constructed, similarly to a diode, from a pair of p-doped and n-doped semiconductors materials. The device is usually build from an array of pairs of n-type and p-type pillars. The pillars reside between two planes. The thermoelectric device is solid and withstand wide range of temperatures. The energy conversion do not involve any moving parts.
Thermoelectric conversion was known to be less efficient than other techniques in the past, but a major progress in recent years both in materials science and device construction increased the efficiency as well as increased the operation temperature. New constructions of material semiconductors based on quantum mechanics principles such as quantum wells and quantum dots further increases the conversion efficiency.
The technology is used today in straight forward heat harvesting or cooling applications. Plain harvesting of heat to electrical energy is thought for example by U.S. Pat. No. 2,519,241 filed on Jul. 5, 1946. Conversion of gas chemical energy to electricity using a gas burner that heat a hot plate that is in contact with a thermoelectric device first plane and a cooling heat sink connected to thermoelectric device second plane is used today as local electricity supply in gas pipe infrastructures. Other applications such as vehicle battery charger from engines exhaust gases (e.g., U.S. patent application Ser. No. 13/861,787 filed on Apr. 12, 2013) or even a cellphone charger from campfires heat are currently in use.
There are also new emerging cooling application such as air condition systems (e.g., U.S. patent application Ser. No. 14/380,937 filed on Feb. 26, 2013), wine cellars, integrated circuits, e.g., CPU, coolers (e.g., U.S. patent application Ser. No. 14/138,593 filed on Dec. 23, 2013) and a compact USB device for beverage can coolers (U.S. patent application Ser. No. 14/202,939 filed on Mar. 10, 2014).
A more complex thermal management system for both heating and cooling for vehicles with a thermoelectric module deployed between the engine cooling system and passenger compartment HVAC system is described in U.S. Pat. No. 7,743,614 issued on Jun. 29, 2010.
All the above mentioned applications are heat to electricity converters or electricity to heat pumping. New ways for using thermoelectric technology integrated with additional elements in a more efficient and intelligent ways, in order to provide new applications, is being taught in the present invention.